Background Frailty is a condition of elderly characterized by increased vulnerability to stressful events with high risk of adverse outcomes. The purpose of this study was to evaluate the association between frailty and adverse outcomes including death and hospitalization due to heart failure in elderly patients. Methods We included patients aged >= 65 years with the diagnosis of heart failure. The clinical and laboratory data, echocardiography and ECGs were recorded. Additionally, the frailty scores of the patients were evaluated according to Canadian Study of Health and Aging. All the patients were divided as frail or non-frail. The groups were compared for their characteristics and the occurrence of clinical outcomes. Results We included 86 eligible patients. The median follow-up time was four months. The mean age was 75 +/- 6.5 years. Of these 86 patients, 17 (19.7%) patients encountered an event (death and/or hospitalization). Nine patients (10.4%) died during follow-up. Thirty patients (34.9%) were considered frail. Among the demographic, clinical and laboratory data, only total protein and albumin levels were found to be lower in frail patients (total protein level: 6.8 +/- 0.6 g/dL in non-frails, 6.5 +/- 0.9 g/dL in frails, P = 0.05; albumin level: 3.8 +/- 0.4 g/dL in non-frails, 3.4 +/- 0.6 g/dL in frails, P = 0.001). In multivariate analysis, frailty was found to be strongly associated with clinical outcomes in short term. Conclusions Being frail in an elderly heart failure patient is associated with death and/or hospitalization due to heart failure in short term. Therefore, frailty score should be evaluated for all elderly heart failure patients as a prognostic marker.